Electric vehicles take a variety of forms, namely pure electric (where the only source of power is a battery), parallel hybrid (where an internal combustion engine or battery may drive the wheels), or series hybrid vehicles where a secondary power source re-charges an on-board battery (a range extender). The present invention is primarily concerned with the latter.
One known approach for operating vehicles with a ‘dual fuel’ range extending functionality is shown in FIG. 3 (referred to as the ‘basic model’). Using this approach, the vehicle is operated purely as an electric vehicle until a predetermined level of charge is reached, at which point the range extender is switched on—and will remain on—until an upper state of charge (SOC) level is reached.
In this basic model, the range extender (RE) is switched on at full power when the SOC reaches the lower threshold; charge is then increased until the upper threshold is reached. The on time of the range extender is indicated by ‘RE State’ 1 being fully on, and 0 being off. This is sometimes referred to as charge depleting/charge sustaining modes (this is a baseline example with another possibility being when the charge sustaining mode is on at less than full power e.g. at efficient power).
The basic model is inefficient because the range extender is typically only used at maximum power (as opposed to where it is most efficient), it does not take into account the most opportune times for range extender usage (only taking into account SOC) and the battery pack will have surplus charge available at the end of the journey (partly generated by the range extender) that could have been used during the discharge cycle. This unused power generated by the range extender will be inherently more expensive than plug in power from the grid. An improved solution is therefore required.
The present invention aims to alleviate at least some of the aforementioned problems.
According to one aspect of the present invention there is provided an apparatus for controlling a range extender in an electric vehicle, the apparatus comprising: means (such as a suitably programmed processor and associated memory) for receiving trip information; means (such as a suitably programmed processor and associated memory) for retrieving power usage information relating to a previous trip, the previous trip having trip information which is at least in part in common with the trip information; and means (such as a suitably programmed processor and associated memory) for activating the range extender in dependence on said power usage information.
The apparatus may further comprise means (such as a suitably programmed processor and associated memory) for determining a power usage plan for said trip in dependence on the retrieved power usage information, and preferably the activating means is adapted to activate the range extender in dependence on said power usage plan.
The power usage plan may comprise an activation schedule.
The activating means may be operable to control the power of the range extender in dependence on the activation schedule.
The power usage plan may comprise a state of battery charge plan for the trip.
The activating means may be operable to control the power of the range extender in dependence on the state of charge plan.
The power usage information may comprise an activation schedule.
The power usage information may be from a local memory.
The power usage information may be determined from externally-sourced trip information.
The power usage information may be from an external data source.
The retrieved power usage information may comprise crowd-sourced power usage information.
The power usage information may comprise information from a logistics database.
The apparatus may further comprise means (such as a suitably programmed processor and associated memory) for determining the state of charge of an on-board battery.
The activation means may be operable to activate the range extender so as to maintain a state of charge of the electric vehicle, preferably in accordance with a state of charge plan.
The state of charge may be maintained so as to follow a linear decrease.
The means for determining the state of charge may be operable to detect charge gradients.
The activation means may be operable to control the power output of the range extender.
The activation means may be adapted to activate the range extender at a low power.
The trip information may comprise a time and/or length of a trip.
The trip information may comprise trip itinerary information.
The apparatus may further comprise telemetry instrumentation, and preferably the receiving means is adapted to receive trip information from the telemetry instrumentation.
The activating means may be operable in dependence on the trip information received from the telemetry instrumentation.
The trip information received from the telemetry instrumentation may comprise a location of the apparatus.
The activation means may be adapted to operate in dependence on the location of the apparatus and a state of charge of an on-board battery.
The received trip information may comprise route information.
The route information may comprise a set of waypoints.
The route information may comprise topographic information.
The trip information may comprise expected speed information.
The trip information may comprise traffic information.
The trip information may comprise non-driving load information.
The non-driving load information may comprise at least one of: heater energy usage, headlight usage, on-board electronics usage, and windshield wiper usage.
The trip information may comprise driver characteristics.
The trip information may comprise payload information.
The trip information may comprise weather information.
The trip information may comprise recharge opportunities.
The apparatus may further comprise means (such as a suitably programmed processor and associated memory) for recording power usage and/or or telemetry information.
The apparatus may further comprise means (such as a suitably programmed processor and associated memory) for uploading power usage information and/or telemetry information to a server.
According to another aspect of the present invention there is provided a range-extended vehicle comprising an apparatus as herein described, preferably connectable to a battery pack, a range extender and an electric motor.
The vehicle may be in the form of a delivery vehicle.
According to another aspect of the present invention there is provided a fleet of vehicles as herein described.
According to another aspect of the present invention there is provided a method for determining a power usage plan for a range-extended electric vehicle, the method comprising: receiving trip telemetry; retrieving power usage information relating to a previous trip, the previous trip having trip information which is at least in part in common with the trip telemetry information; and determining a power usage plan to be associated with said trip telemetry in dependence on the retrieved power usage information.
The trip telemetry may comprise at least one of: location, speed, acceleration, elevation, time of day, driver characteristics, and weather.
The power usage plan may be updated when the trip telemetry does not match the power usage plan.
The method may further comprise uploading said trip telemetry information and/or power usage information to a server.
According to another aspect of the present invention there is provided a computer program product adapted to carry out the method described herein.
The computer program product may be in the form of a software application adapted to be executed on a portable computing device.
According to another aspect of the present invention there is provided a system comprising: at least one vehicle as herein described; and a server operable to transmit and/or receive trip information and/or power usage information to and/or from said vehicles.
The system may further comprise a vehicle incorporating the computer program product described herein.
The system may further comprise a further vehicle carrying a device adapted to execute the computer program product as described herein.
According to another aspect of the present invention there is provided a method for regulating the battery usage of a range-extended vehicle, the method comprising: receiving a power usage plan for a trip itinerary; monitoring the state of charge of an on-board battery for powering said vehicle; and activating the range extender if the state of charge is lower than the corresponding level on the power usage plan.
The power usage plan may comprise a low state of charge at the end of the trip.
The power usage plan may comprise a linear decay of the state of charge of the battery.
The power usage plan may comprise a first section where the state of charge is substantially constant, and a second section wherein the state of charge follows a linear decay.
The range extender may be activated when the state of charge is at least substantially 5% lower than the corresponding level on the power usage plan.
The range extender may be activated when the state of charge is at least substantially 10% lower than the corresponding level on the power usage plan.
According to another aspect of the present invention there is provided a method for controlling a range extender in an electric vehicle, the method comprising: receiving trip information, retrieving at least one previous trip having trip information in common with the trip information, and having associated power usage information; and activating the range extender in dependence on said power usage information.
The method may further comprise: determining a power usage plan for said trip itinerary in dependence on the retrieved power usage information;
In the absence of sufficient trip information and/or power usage information, a default power usage plan may be determined.
The default usage plan may be one of: a recently used power usage plan, a commonly used power usage plan, a power usage plan with an early discharge phase and a later charge-sustaining phase.
The invention also extends to an apparatus for controlling a range extender in an electric vehicle substantially as described herein and/or with reference to the accompanying drawings.
The invention also extends to a method for regulating the battery usage of a range-extended vehicle substantially as described herein and/or with reference to the accompanying drawings.
The invention also extends to a method for controlling a range extender in an electric vehicle substantially as described herein with and/or reference to the accompanying drawings.
The invention also extends to a range-extended vehicle substantially as described herein and/or with reference to the accompanying drawings.
The invention extends to any novel aspects or features described and/or illustrated herein. Further features of the invention are characterised by the independent and dependent claims.
Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa.
The invention also provides a computer program and a computer program product comprising software code adapted, when executed on a data processing apparatus, to perform any of the methods described herein, including any or all of their component steps.
The invention also provides a computer program and a computer program product comprising software code which, when executed on a data processing apparatus, comprises any of the apparatus features described herein.
The invention also provides a computer program and a computer program product having an operating system which supports a computer program for carrying out any of the methods described herein and/or for embodying any of the apparatus features described herein.
The invention also provides a computer readable medium having stored thereon the computer program as aforesaid.
The invention also provides a signal carrying the computer program as aforesaid, and a method of transmitting such a signal.
Furthermore, features implemented in hardware may be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly.
Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.
It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.
The entire contents of U.S. Provisional patent application No. 61/736,050 relating to ‘Predictive Range Extender Management’ is hereby incorporated herein by reference in its entirety.
In this specification the word or can be interpreted in the exclusive or inclusive sense unless stated otherwise.
The invention extends to methods and/or apparatus substantially as herein described with reference to the accompanying drawings.